Golf Putter Head with Maximized Fore-Aft Weighting and Vertical Sweetspot

ABSTRACT

This invention maximizes the distribution of mass of the club head to the front and back of the club head to maximize the sweetspot vertically. Mass is concentrated in front and back bars. Mass is minimized in between the bars by use of light weight tubes, one at the heel and one at the toe, that connect the front and back bars to each other. A screw inside each tube cinches the bars against the tubes. A hosel is on the heel tube. The lie of the club is adjustable by loosening the heel side cinching screw which allows the heel tube to turn against the bars. Forward press is adjustable by loosening set screws and turning the bent golf shaft in the hosel. Weights can be added and removed within the tubes to adjust the club head weight.

BACKGROUND OF THE INVENTION

This regards golf clubs, specifically the club head of the putter. Putters are sometimes designed to improve the steadiness of the club head from an off center hit of the ball. For example, a putter with mass concentrated at the heel and toe portions of the head increases steadiness of the head by reducing twisting when the ball contacts off-center toward the heel or toe. Reduced twisting preserves better the direction and distance of the golf ball travel. Another way to stabilize or steady a club head is to concentrate mass to the front and back of the head. Golf clubs with elongated heads in the fore-aft dimension, such as woods and mallet putters, are more impervious to off center hits that hit high or low on the club face. Reduced rotation of the head about a horizontal heel-toe axis passing near the center of mass gives better distance control and a much greater solid feeling. The further the mass of the putter is located to the front and rear, the greater the effect. This applicant has a patent for a four corner weighted putter, patent 4,010,958, that provides high rotational inertia of the two types: about the vertical axis through the center of mass, and about a heel-toe axis through the center of mass. That patent maximized mass distribution away from the center of mass into the four corners. This invention concentrates on maximizing distribution of mass forward and backward without concentrating in the corners, which led to a new structural solution.

Just to be clear, the front of the club head is the side that has the club face, which is where the ball is struck.

Putters are often designed to look good or look effective. Putter heads can also be designed to aid in alignment to the target by having lines or edges that are parallel or perpendicular to the intended direction of ball travel. Putters are also usually designed to conform to the official golf rules. One rule states that the head may not be bigger from front to back than it is from heel to toe.

SUMMARY OF THE INVENTION

The idea behind this club head design is to maximize the mass distribution to the front and rear of the head, and minimize the mass between the front and rear so as to increase the stability of the head to ball strikes that hit high and low on the club face. Of course there has to be some structure between the front and rear so as to hold the head together and connect it to a golf shaft or handle. It is this internal structure’s mass that is minimized while keeping enough strength to prevent breakage.

The club head comprises four struts or elongated members forming a square or rectangular shape. There are two kinds of struts: a heavy type and a light type. The heavy struts are deployed to the front and rear; the light struts are deployed to the heel and toe. The rest of the head, the interior, remains empty. The heavy struts contribute more to the design if they are made of the highest density material available or affordable. The light struts contribute more if they are made of the lowest density material that is affordable and strong enough. In the preferred embodiment, the heavy struts can be made of stainless steel bars and the light weight struts can be made of carbon fiber composite tube. These factors concentrate the mass of the putter head to the front and to the rear of the head, distant from the center of mass. The further the mass is from the center of mass, the greater it increases the stability or rotational inertia of the putter head. And the greater the rotational inertia, the bigger the sweet spot size for the golfer who wants to have a solid and accurate hit despite contacting the ball away from the perfect spot on the club face. By concentrating the mass to the front and rear, as opposed to the heel and toe, the sweet spot is expanded mostly in a vertical direction on the club face.

The carbon fiber composite tubes are held in place by shallow circular grooves in the bars into which the tube ends fit, and by a long screw inside each tube which pulls the front and back bars toward each other against the tubes.

A golf shaft with a grip for the golfer’s hands is fastened to the club head. The shaft is fastened to the head by a hosel mounted on the heel side tube. The hosel has a ring bonded to the carbon fiber tube. The lie of the club is adjustable by loosening the screw that holds the carbon fiber tube in position against the bars, allowing the tube and hosel to turn in relation to the bars.

The golf shaft is adjustable in its forward press because it is held with set screws in a socket on the hosel. The golf shaft is bent just above the socket, so turning the shaft in the socket moves the golf grip and shaft forward and backward (to and from the target) to suit golfer preference.

The two light struts are located close to the heel and toe, rather than more centrally, so as to increase heel-toe weighting and twist resistance of the club head for balls hit off-center toward the heel or toe, and in addition, for strength and for club head appearance.

With all four struts located at the edges of the club head, and the midsection empty of mass, rotational inertia is increased around both axes.

Increasing the distance from the front to the back increases the rotational inertia about the horizontal heel-toe axis, but there is a limitation to the rearward mass distribution by a rule of the United States Golf Association (U.S.G.A.) and the Royal and Ancient (R & A). The rule states the front to back distance of the head must be less than the heel to toe distance. Using the maximum allowed by this rule, the applicant’s club head assumes a nearly square shape.

Further increased rotational inertia about the vertical axis could be obtained by redistributing the mass of the front and back members toward the corners of the head, by altering the shapes of the front and back bars. But this would reduce the vertical sweet spot and complicate the appearance of the head.

The bars and tubes are straight and straight edged, which benefits the aiming of the head at the target and keeps the appearance clean and simple.

To add mass to the putter head, the front and back bars can be made thicker or longer. Another way to add mass is to put metal plugs in the ends of the tubes. For the golfer to adjust the mass, weights are placed on the screws inside the tubes. Mass added inside the toe side tube can counterbalance the mass of the hosel on the heel side.

Overall size of the head is open to personal choice, up to the seven inch heel to toe limit by a golf rule. Smaller heads use shorter bars which must be thicker, for given a head weight.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 Perspective view of the club head.

FIG. 2 Sectioned plan view, showing the bottom half of the club head.

DETAILED DESCRIPTION

The following describes the preferred embodiment as shown in FIGS. 1 and 2 . In FIG. 1 , the putter head 10 has two stainless steel bars, front bar 12 and back bar 14, deployed to the front and back of the putter head, parallel to each other. Each bar has a cross-section 20 mm by 10 mm and a length of 100 mm. The 20 mm sides face forward and backward, so the golfer sees the 10 mm side from above. These bars are separated and fixed by two 15 mm diameter round carbon fiber composite tubes 18 (the heel tube) and 20 (the toe tube). The tubes have a wall thickness of around 1 mm. The carbon fiber composite tubes contact the bars on the 20 mm inward facing sides of the bars, near the ends of the bars. The tubes should be parallel to each other and perpendicular to the bars. The carbon fiber composite tubes have a length of 80 mm to create a near square club head. The front bar acts as the club face 16, where the ball is struck.

Seen in FIG. 2 , the ends of tubes 18 and 20 are located on the bars 12 and 14 by 1 mm deep grooves 24 in the bars. M5 cap screws 26 and 28 are used to cinch the bars against the tubes. The cap screws pass through the longitudinal central axes of the tubes. The cap screw heads are located in counterbores on the back of bar 14 so the heads do not stick out beyond the surface of the bar. The cap screws are screwed into blind threaded holes in front bar 12. Loft for the club face 16 is created by machining the shallow grooves and threaded holes at a 2 degree angle rather than perpendicular to the club face. The overall depth of the head from club face to the back of the back bar is almost 100 mm.

Back on FIG. 1 , a 2 cm long metal ring 22 is installed over the carbon fiber composite tube 18. Adhesive fixes the ring to the tube. Before installing ring 22, weld to it a socket 28, perpendicular to the ring, to accept a golf shaft 30. Fasten the golf shaft in the socket with two M4 set screws 32. Set screws 32 sit in thickened spots on socket 28 to create enough threads. Ring 22 and socket 28 could also be created as one by casting. The golf shaft 30 should have a bend 34 just above the socket to get the golf shaft’s main axis (located above the bend) to pass through the club head about halfway between the heel and toe tubes. The putter head looks and works better if ring 22 is positioned closer to the front bar than to the rear bar. The set screws 32 allow the adjustment of the forward press by the golfer. The forward press is the position of the golfer’s hands to the golfer’s left or right. Loosening bolt 26 allows the putter head to rotate about the axis of the tube 18, giving the golfer a convenient way to adjust the lie of the club. The lie and forward press should be adjusted on a flat level surface. If the lie or forward press won’t stay set, the metal contact surfaces can be roughened or friction granules can be applied.

The front and back bars of the preferred embodiment have straight flat lower surfaces and are designed to be adjusted by the golfer to sit flat on a level surface at address. Golf greens, however, are hardly ever level. Therefore the golfer cannot always rest the head flat on the green. There are ways to deal with this that become evident upon using the preferred embodiment. Nevertheless, some golfers may want the putter head to touch the ground in the traditional way. Blade putters touch the grass under the middle of the blade. The front bar of the preferred embodiment could serve as resting point similar to a blade putter, by adding a bulge under the middle of the front bar and/or elevating the back bar. Another modification to the preferred embodiment for resting on sloped greens is to add a strut that extends into the centralized area of the head and descends downward below the head about ⅛ inch. If the strut is added to the toe carbon fiber tube, the strut has the added benefit of being adjustable up and down, because the tube is rotatable when loosened.

A more expensive and slightly improved embodiment uses tungsten carbide front and rear bars, whose higher density provides more rotational inertia through greater concentration of mass to the front and rear than does steel, and also provides greater scratch resistance for maintaining appearance.

Another modification that might please some golfers is to make the front and back bars into a traditional shape. One or both bars can have a flange or lip that sticks out from the lower part of the bar. The front bar would have the flange stick out toward the rear of the head. The back bar could have flange facing forward or backward. This would lower the center of gravity and sacrifice some rotational inertia.

An alteration to the preferred embodiment (not shown) could use caps in or on the ends of the tubes, with a threaded hole for a short screw going through the bar at each end rather than one long screw through the tube. This sacrifices the important feature of adding and subtracting weights inside the tubes by the consumer, but it could slightly increase the distribution of mass to the front and back of the club head. 

I claim:
 1. A golf club comprising a club head, a golf shaft, and a golf shaft attaching means attaching the golf shaft to the head, in which said club head comprises a. a front bar, at the front of the club head, disposed from heel to toe, with a ball striking surface on the front-facing side, with tube cinching means, and tube locating means near each end, b. a back bar, at the back of the club head, disposed from heel to toe, with tube cinching means, and tube locating means near each end, c. a heel tube, toward the heel of the club head, spanning between the front and back bars, positioned on the bars by the tube locating means, and held against the bars by cinching means, d. a toe tube, toward the toe of the club head, spanning between the front and back bars, positioned on the bars by the tube locating means, and held against the bars by cinching means, e. the front bar and back bar, in the plan view, appear to be at right angles to the heel and toe tubes.
 2. A golf club of claim 1 wherein the cinching means includes an elongated cinching member inside each tube, connecting to the bars, to cinch the bars against the tubes.
 3. A golf club of claim 1 wherein the tube locating means is a recess in the bar, into which the tube fits.
 4. A golf club of claim 1 wherein the golf shaft attaching means is located on the heel tube.
 5. A golf club of claim 4 wherein the golf shaft attaching means comprises (a) a golf shaft receiving tube, and (b) a means of fixing the golf shaft receiving tube to the heel tube.
 6. A golf club of claim 5 wherein the means of fixing the golf shaft receiving tube to the heel tube is a ring on the heel tube.
 7. A golf club of claim 4 wherein the golf shaft is fixed in the golf shaft receiving tube by a retaining means which allows the shaft to be turned and fixed in a new position.
 8. A golf club of claim 7 wherein the retaining means is one or more set screws in the golf shaft receiving tube, such that the tightened set screws press against the golf shaft.
 9. A golf club of claim 2 in which club head lie is adjusted by loosening the elongated cinching member at the heel of the club head, revolving the club head about the heel tube, and then retightening the elongated cinching member.
 10. A golf club of claim 8 wherein the golf shaft has a bend near the golf shaft receiving tube, and an adjustment of forward press is made by loosening the set screws, turning the golf shaft in the golf shaft receiving tube, and re-tightening the set screws.
 11. A golf club of claim 2 wherein the elongated cinching member has mass added detachably to it.
 12. A golf club of claim 1 wherein the bars are made of a dense material such as steel, and the tubes are made of light material such as carbon fiber composite.
 13. A golf club of claim 4 wherein the golf shaft attaching means allows the golf shaft to be unfixed, turned to consumer preference, and fixed again. 